fmc: Delete the FMC subsystem

The FMC subsystem was created in 2012 with the ambition to
drive development of drivers for this hardware upstream.

The current implementation has architectural flaws and would
need to be revamped using real hardware to something that can
reuse existing kernel abstractions in the subsystems for e.g.
I2C, FPGA and GPIO.

We have concluded that for the mainline kernel it will be
better to delete the subsystem and start over with a clean
slate when/if an active maintainer steps up.

For details see:
https://lkml.org/lkml/2018/10/29/534

Suggested-by: Federico Vaga <federico.vaga@cern.ch>
Cc: Pat Riehecky <riehecky@fnal.gov>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 0 insertions, 98 deletions

diff --git a/Documentation/fmc/fmc-write-eeprom.txt b/Documentation/fmc/fmc-write-eeprom.txt
deleted file mode 100644
index e0a9712156aa..000000000000
--- a/Documentation/fmc/fmc-write-eeprom.txt
+++ /dev/null
@@ -1,98 +0,0 @@
-fmc-write-eeprom
-================
-
-This module is designed to load a binary file from /lib/firmware and to
-write it to the internal EEPROM of the mezzanine card. This driver uses
-the `busid' generic parameter.
-
-Overwriting the EEPROM is not something you should do daily, and it is
-expected to only happen during manufacturing. For this reason, the
-module makes it unlikely for the random user to change a working EEPROM.
-
-However, since the EEPROM may include application-specific information
-other than the identification, later versions of this packages added
-write-support through sysfs. See *note Accessing the EEPROM::.
-
-To avoid damaging the EEPROM content, the module takes the following
-measures:
-
-   * It accepts a `file=' argument (within /lib/firmware) and if no
-     such argument is received, it doesn't write anything to EEPROM
-     (i.e. there is no default file name).
-
-   * If the file name ends with `.bin' it is written verbatim starting
-     at offset 0.
-
-   * If the file name ends with `.tlv' it is interpreted as
-     type-length-value (i.e., it allows writev(2)-like operation).
-
-   * If the file name doesn't match any of the patterns above, it is
-     ignored and no write is performed.
-
-   * Only cards listed with `busid=' are written to. If no busid is
-     specified, no programming is done (and the probe function of the
-     driver will fail).
-
-
-Each TLV tuple is formatted in this way: the header is 5 bytes,
-followed by data. The first byte is `w' for write, the next two bytes
-represent the address, in little-endian byte order, and the next two
-represent the data length, in little-endian order. The length does not
-include the header (it is the actual number of bytes to be written).
-
-This is a real example: that writes 5 bytes at position 0x110:
-
-        spusa.root# od -t x1 -Ax /lib/firmware/try.tlv
-        000000 77 10 01 05 00 30 31 32 33 34
-        00000a
-        spusa.root# insmod /tmp/fmc-write-eeprom.ko busid=0x0200 file=try.tlv
-        [19983.391498] spec 0000:03:00.0: write 5 bytes at 0x0110
-        [19983.414615] spec 0000:03:00.0: write_eeprom: success
-
-Please note that you'll most likely want to use SDBFS to build your
-EEPROM image, at least if your mezzanines are being used in the White
-Rabbit environment. For this reason the TLV format is not expected to
-be used much and is not expected to be developed further.
-
-If you want to try reflashing fake EEPROM devices, you can use the
-fmc-fakedev.ko module (see *note fmc-fakedev::).  Whenever you change
-the image starting at offset 0, it will deregister and register again
-after two seconds.  Please note, however, that if fmc-write-eeprom is
-still loaded, the system will associate it to the new device, which
-will be reprogrammed and thus will be unloaded after two seconds.  The
-following example removes the module after it reflashed fakedev the
-first time.
-
-     spusa.root# insmod fmc-fakedev.ko
-        [   72.984733]  fake-fmc: Manufacturer: fake-vendor
-        [   72.989434]  fake-fmc: Product name: fake-design-for-testing
-        spusa.root# insmod fmc-write-eeprom.ko busid=0 file=fdelay-eeprom.bin; \
-            rmmod fmc-write-eeprom
-        [  130.874098]  fake-fmc: Matching a generic driver (no ID)
-        [  130.887845]  fake-fmc: programming 6155 bytes
-        [  130.894567]  fake-fmc: write_eeprom: success
-        [  132.895794]  fake-fmc: Manufacturer: CERN
-        [  132.899872]  fake-fmc: Product name: FmcDelay1ns4cha
-
-
-Accessing the EEPROM
-=====================
-
-The bus creates a sysfs binary file called eeprom for each mezzanine it
-knows about:
-
-        spusa.root# cd /sys/bus/fmc/devices; ls -l */eeprom
-        -r--r--r-- 1 root root 8192 Feb 21 12:30 FmcAdc100m14b4cha-0800/eeprom
-        -r--r--r-- 1 root root 8192 Feb 21 12:30 FmcDelay1ns4cha-0200/eeprom
-        -r--r--r-- 1 root root 8192 Feb 21 12:30 FmcDio5cha-0400/eeprom
-
-Everybody can read the files and the superuser can also modify it, but
-the operation may on the carrier driver, if the carrier is unable to
-access the I2C bus.  For example, the spec driver can access the bus
-only with its golden gateware: after a mezzanine driver reprogrammed
-the FPGA with a custom circuit, the carrier is unable to access the
-EEPROM and returns ENOTSUPP.
-
-An alternative way to write the EEPROM is the mezzanine driver
-fmc-write-eeprom (See *note fmc-write-eeprom::), but the procedure is
-more complex.